High speed plate pick up device

ABSTRACT

A system for removing an interleaf sheet contacting a plate sheet used in an imaging system, comprised of a substantially horizontal member; an assembly comprising at least two elements configured to directly contact and pick up the interleaf sheet, a portion of said assembly connected to said member; a motor configured to move said member in a direction substantially perpendicular to a surface of the interleaf sheet as positioned prior to contact; and a first sensor system that generates a signal indicating when said member is a first predetermined distance from the interleaf sheet; and a second sensor system comprised of a second sensor that generates a signal indicating that the sheet beneath the second sensor is an interleaf sheet; said motor utilizing the first predetermined distance to move said member a second predetermined distance from the interleaf sheet, the at least two elements not contacting each other at the second predetermined distance, said motor moving said member in a direction toward the first predetermined distance to a position where at least a portion of the interleaf sheet is interposed between the at least two elements.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application claims priority based upon patent application60/880,893, the entire disclosure of which is hereby incorporated byreference into this specification. This application also is acontinuation-in-part of applicants' copending patent application U.S.Ser. No. 11/296,527, filed on Dec. 8, 2005, which was published as (U.S.2006/0117975) on Jun. 8, 2006. The entire disclosure of such patentapplication is hereby incorporated by reference into this specification.

FIELD OF THE INVENTION

A system for removing and/or separating an interleaf sheet from a platesheet and/or transporting a plate sheet that is used in conjunctionwith, e.g., a Computer-to-Plate imaging system.

BACKGROUND OF THE INVENTION

Published United States patent application US 2006/0117975 relatesgenerally to a system and method for removing and/or separating aninterleaf sheet from a plate sheet and/or transporting a plate sheet,used in connection with, for example, Computer-to-Plate (CTP) imagingsystems. As is described in paragraph 0005 of such published patentapplication, “Automating the printing process in CTP imaging systemsinvolves the alternating process of extracting plate sheet material, andthen interleaf sheet material, from a material stack. Images are exposedon the plate sheet material, and the interleaf sheet material is used toprotect the imaging surface of plate sheets from each other.”

In paragraph 0007 of such patent application, it is disclosed that“Extracting the interleaf sheets manually is labor intensive, butnormally does not present other issues or challenges. However,automating the process for extracting interleaf sheets can bechallenging. For example, interleaf sheets can adhere onto the imagingsurface of the plate sheet because of, for example, friction and/orstatic. Known CTP systems that automate the removal of interleaf sheets,such as disclosed in U.S. Pat. No. 5,655,452, which is in incorporatedherein by reference, use at least a combination of a suction cup and airblast. However, due to the porous nature of the interleaf sheet,reliability issues are generally present when suction cups are used toremove interleaf sheets.”

Claim 1 of published patent application US 2006/0117975 discusses asystem for removing an interleaf sheet, describing: “1. A system forremoving an interleaf sheet contacting a plate sheet used in an imagingsystem, comprising: a substantially horizontal member; an assemblycomprising at least two elements configured to directly contact and pickup the interleaf sheet, a portion of said assembly connected to saidmember; a motor configured to move said member in a directionsubstantially perpendicular to a surface of the interleaf sheet aspositioned prior to contact; and a sensor system that generates a signalindicating when said member is a first predetermined distance from theinterleaf sheet; said motor utilizing the first predetermined distanceto move said member a second predetermined distance from the interleafsheet, the at least two elements not contacting each other at the secondpredetermined distance, said motor moving said member in a directiontoward the first predetermined distance to a position where at least aportion of the interleaf sheet is interposed between the at least twoelements.”

Claim 36 of published patent application US 2006/0117975 discusses asystem for picking up plate, describing: “36. A system for raising aplate sheet for use in an imaging system comprising an imager,comprising: a substantially horizontal member; at least one elementconfigured to directly contact and vertically raise the plate sheet, aportion of said at least one element connected to said member; a motorconfigured to raise said member in a direction substantiallyperpendicular to a surface of the plate sheet as positioned prior tocontact; and a sensor system that generates a signal indicating whensaid member is a first predetermined distance from the plate sheet; saidmotor utilizing the first predetermined distance to move said member asecond predetermined distance, thereby raising the plate sheet.”

Claim 41 of published patent application US 2006/0117975 depends uponsuch claim 36 and further describes a rail system for moving the platesheet as follows: “41. The system according to claim 36, furthercomprising a rail system for moving the plate sheet in a direction awayfrom the imager, to thereby substantially align a trailing edge of theplate sheet with a trailing edge of a second plate sheet positionedbeneath said plate sheet.”

The devices utilized in the prior art (such as, e.g., the devicesdescribed by such claims 1, 36, and 41) utilize a one-arm assembly topick up plates out of a cassette and transfer them into an imagingsystem; that same arm assembly is also used to pick up interleaf sheetsand dispose the interleaf sheets into a chute. As described hereinabove,and with reference to such published patent application, claim 1describes the system for removing the interleaf sheets, claim 36describes the system for picking up plates, and claim 41 describes therail system that the arras travels on. The published patent applicationpatent shows both the interleaf removal mechanism and the plate pickmechanism on the same arm assembly.

It is an object of this invention to provide a device with asubstantially greater speed of operation than the prior art devices and,in particular, than the device disclosed in published United Statespatent application 2006/0117975.

SUMMARY OF THE INVENTION

In accordance with this invention, there is provided a system forremoving an interleaf sheet contacting a plate sheet used in an imagingsystem, comprised of a substantially horizontal member; an assemblycomprising at least two elements configured to directly contact and pickup the interleaf sheet, a portion of said assembly connected to saidmember; a motor configured to move said member in a directionsubstantially perpendicular to a surface of the interleaf sheet aspositioned prior to contact; and a first sensor system that generates asignal indicating when said member is a first predetermined distancefrom the interleaf sheet; and a second sensor system comprised of asecond sensor that generates a signal indicating that the sheet beneaththe second sensor is an interleaf sheet; said motor utilizing the firstpredetermined distance to move said member a second predetermineddistance from the interleaf sheet, the at least two elements notcontacting each other at the second predetermined distance, said motormoving said member in a direction toward the first predetermineddistance to a position where at least a portion of the interleaf sheetis interposed between the at least two elements.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by reference to specification and theaccompanying Figures, in which like numerals refer to like elements, andwherein:

FIG. 1 is a perspective view of a Computer-to-Plate (CTP) imagingsystem;

FIG. 2 is a perspective view of an exemplary interleaf sheet removal andplate sheet transport apparatus;

FIG. 3 is a second perspective view of the exemplary interleaf sheetremoval and plate sheet transport apparatus, and disposal rollers;

FIG. 4 is a perspective view of an exemplary embodiment of an interleafsheet removal roller apparatus;

FIGS. 5A-5D is a sequence of operations showing how the interleaf sheetremoval roller apparatus can be used to pick up an interleaf sheet;

FIG. 6A is a front view of a second embodiment of an interleaf sheetremoval roller apparatus;

FIG. 6B is a perspective view of a second embodiment of an interleafsheet removal roller apparatus;

FIG. 7A is a front view of a third embodiment of an interleaf sheetremoval roller apparatus;

FIG. 7B is a perspective view of a third embodiment of an interleafsheet removal roller apparatus;

FIGS. 8A-8D is a sequence of operations showing how a fourth embodimentof an interleaf sheet removal roller apparatus can be used to pick up aninterleaf sheet;

FIG. 9 is a perspective view of a second embodiment of an exemplaryinterleaf sheet removal apparatus;

FIG. 10 is a second perspective view of a second embodiment of anexemplary interleaf sheet removal apparatus;

FIGS. 11A-11D is a sequence of operations showing how a secondembodiment of the interleaf sheet removal apparatus can be used to pickup an interleaf sheet;

FIG. 12 is a perspective view of a preferred Computer-to-Plate (CTP)imaging system;

FIG. 13 is a perspective view of a high speed dual pick-up arm apparatusthat preferably comprises the system of FIG. 12;

FIG. 14 is an enlarged perspective view of the pick-up arm apparatus ofFIG. 13;

FIG. 15 is a perspective view of a plate pick-up apparatus thatpreferably comprises the system of FIG. 12;

FIG. 16 is a perspective view of an interleaf removal apparatus thatpreferably comprises the system of FIG. 12; and

FIG. 17 is a schematic of an interleaf disposal and scissor releasesystem that preferably comprises the system of FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates generally to a system and method forremoving and/or separating an interleaf sheet from a plate sheet and/ortransporting a plate sheet, used in connection with, for example,Computer-to-Plate (CTP) imaging systems.

FIG. 1 is a perspective view of a Computer-to-Plate (CTP) imaging system100 that can be used in connection with the interleaf sheet removal andplate sheet transport apparatus 114 (apparatus 114) and/or portionsthereof in accordance with certain embodiments of the present invention.The system 100 includes a cassette assembly 102 that can hold platesheets (not shown) and associated interleaf sheets (not shown). Cassetteinterface 104 can be used to load the cassette assembly 102 withalternating plate sheets and interleaf sheets in a conventional manner.Apparatus 114 can be used to remove interleaf sheets from plate sheets,remove plate sheets from interleaf sheets, dispose the interleaf sheetsin funnel assembly 106, and/or transport plate sheets to input shelf108. Vacuum pump 118 is used to generate a suction so that suction cupscan hold and transport a plate sheet. When the plate sheets are receivedat input shelf 108, imaging apparatus 110 generally utilizes one or morelasers to perform plate sheet imaging in a conventional manner. Outputplatform 112 receives imaged plate sheets.

FIGS. 2 and 3 show perspective views of apparatus 114. Apparatus 114includes member 202, which can be used to receive a portion of rollerassemblies 200 a, 200 b. Roller assemblies 200 a, 200 b can be used topick up and remove interleaf sheets, as will be described below. Member202 can also be used to receive a portion of suction cups 206 a, 206 b.Suction cups 206 a, 206 b can be used to pick up and remove plate sheets335, and feed (transport) them to input shelf 108 and imaging apparatus110. Prior to roller assemblies 200 a, 200 b picking up an interleafsheet, an interleaf sheet will be substantially horizontal, as platesheet 335 is shown in FIG. 3.

Rail apparatus 116 can be used to move apparatus 114 in the direction ofarrows 226, 228. Optical sensor 244, which can be mounted in a fixedposition, and having teeth 244 a, 244 b, can be used to control movementof apparatus 114. Flag 248 can be received between teeth 244 a, 244 b toblock an optical signal between the teeth. When the optical circuit iscompleted between teeth 244 a, 244 b, movement in direction 226, 228 canbe stopped. Optical sensors 238, 240, and 242 can be configured the sameas or similarly to sensor 244 to control movement and/or position, aswill be described herein.

Rail apparatus 116 can include a mounting plate 222 which, in turn, issecured to member 250. Motor 208 is used to drive shaft 216 which, inturn, moves apparatus 114 in the direction of arrows 230, 232. Shaft 216can be, for example, a conventional screw shaft. Member 250 can beattached to or be an integral part of mounting plate 222. Horizontalslide rail 218 can be attached to or an integral part of member 250.Vertical plate 252 can have an attachment or integral part thereof thatmates with and receives horizontal slide rail 218 to facilitate movementof apparatus 114 in the direction of arrows 230, 232. The length ofshaft 216 and/or collar 256 contact with member 202 can be used to limitmovement of apparatus 114 in the direction of arrow 230. Flag 254 andsensor 242 are used to limit movement of assembly in the direction ofarrow 232.

Sensor 238 may used to indicate that member 212 is at or near a homeposition. Flag 266 is attached to or integral with, for example, abottom surface of motor mount 270. When member 212, having sensor 240attached thereto, moves in the direction of arrow 236, a home positioncan be determined when flag 266 cuts of the signal between the teeth ofsensor 238. In FIG. 2, member 212 is shown in the home position.

Motor 210 is used to drive shaft 258 which, in turn, moves apparatus 114in the direction of arrows 234, 236. Shaft 258 may be, for example, aconventional screw shaft. Vertical position member 212 can have anattachment or integral part thereof that mates with and receivesvertical slide rail 262 to facilitate movement of apparatus 114 in thedirection of arrows 234, 236. Flag 248 and sensor 240 are used todetermine the distance of member 202 from an interleaf sheet or platesheet 335. The length of shaft 258 and/or collar 260 contact a topsurface of motor 210, and is used to limit movement of apparatus 114 inthe direction of arrow 234.

Plate height sensor member 205 can be used to determine the distance ofmember 202 from an interleaf sheet or a plate sheet 335. When sensormember 205 contacts an interleaf sheet or plate sheet 335, member 202continues to move in the direction of arrow 234, and shaft 264 willremain stationary relative to interleaf sheet or plate sheet 335. Flag248 can be attached to or integral with a top portion of shaft 248, suchthat as member 202 continues to move in the direction of arrow 234, flag248 will block the optical signal of sensor 240. The blocking of theoptical signal can be associated with a distance of member 202 to aninterleaf sheet or plate sheet 335.

In the case of an interleaf sheet, motor 210 continues to drive member202 in the direction of arrow 234, and thereby activate rollerassemblies 200 a, 200 b, as will be described herein. Movement of member202 in the direction of arrow 234 is not normally limited by collar 224contacting a bottom surface of member 202 and/or collar 260 contacting atop surface of motor 210. Movement of member 202 in the direction ofarrow 234 is of a predetermined distance, starting from the time whenmember 205 makes contact with the interleaf sheet, to the time when flag248 blocks the optical signal of sensor 240. This predetermined distancemay be optimized to best secure the interleaf sheet between rollers 202a, 204 a and 202 b, 204 b. After an interleaf sheet is received betweenrollers 202 a, 204 a and 202 b, 204 b, motor 210 is used to raiseapparatus 114 in the direction of arrow 236.

When apparatus 114 removes an interleaf sheet, rail apparatus 116 canthen be activated to move apparatus 114 in the direction of arrow 226,to position the interleaf sheet over disposal rollers 302 a, 302 b.Disposal rollers can be driven by at least one motor and belt assembly(not shown) to rotate rollers 302 a, 302 b respectively in the directionof arrows 304 a, 304 b. Motor 210 can be used to lower apparatus 114 inthe direction of arrow 234 so that the interleaf sheet contacts thedisposal rollers 302 a, 302 b and conveys the interleaf sheet to rollers302 a, 302 b. Upon disposing of the interleaf sheet, motor 210 can beused to raise apparatus 114 in the direction of arrow 236. Railapparatus 116 can be used to move apparatus 114 in the direction ofarrow 228, so that suction cups 206 a, 206 b can pick up a plate sheet335, and feed the plate sheet 335 to input shelf 108 for subsequentimaging.

In the case of a plate sheet 335, vacuum pump 118, operatively connectedto suctions cup 206 a, 206 b by, for example, one or more hoses, isactivated. The suctions cups 206 a, 206 b, by vacuum, hold the platesheet 335 in contact with the vacuum cups 206 a, 206 b. Movement ofmember 202 in the direction of arrow 234 is again limited by apredetermined distance. After an interleaf sheet is received betweenrollers 202 a, 204 b and 202 b, 204 b, motor 210 can be used to raiseapparatus 114 in the direction of arrow 236.

Once the suction cups 206 a, 206 b contact a plate sheet 335, in oneembodiment of the invention, the following sequential, non-sequential orsequence independent operations may take place. Referring to FIG. 1,assembly 114 is moved in proximity to an edge of the plate sheet 335. Anedge of the plate sheet 335 is preferred because static forces andvacuum forces are generally weaker there. Vacuum pump 118 is activatedto provide a vacuum to suction cups 206 a, 206 b. Apparatus then movesin the direction of arrow 236, thus lifting plate sheet 335. In oneembodiment, the plate sheet 335 can be lifted approximately 10 mm.

The plate sheet 335 is held in the raised (in the direction of arrow236) position for approximately 3-5 seconds, thereby allowing aninterleaf sheet that may be adhering to a bottom surface of the platesheet 335, in the vast majority of cases, to separate and fall back into place to the stack. The interleaf may not fall/separate from thebottom of the plate sheet 335 in all instances. To minimize any relativemotion between the interleaf sheet and the plate sheet 335 under thesecircumstances, apparatus 114, holding plate sheet 335, moves further inthe direction of arrow 236, and slightly in the direction of arrow 228to minimize or eliminate any sliding of the plate sheet 335 relative tothe interleaf sheet underneath the plate. Relative motion may be causedby sagging at the opposing end of the plate sheet 335 from which thesuction cups 206 a, 206 b are holding the plate sheet 335. The saggingcauses the opposing end of the plate sheet 335 to drop vertically. Theopposing edge of the plate sheet 335, by virtue of dropping vertically,also moves slightly toward suction cups 206 a, 206 b (in the directionof arrow 226), which is compensated for by the apparatus 114 moving inthe direction of arrow 228.

Whether or not the interleaf sheet has dropped back to the stack oradheres to the bottom of the plate sheet 335, ionizer 272 is activated,which creates an air cushion. A compressed air cylinder (not shown) maybe used in conjunction with ionizer 272, which causes static charges todissipate. Any interleaf sheet that may have been adhering to the bottomof the plate sheet 335 will now fall back to the stack. In either case,static charges will be dissipated. Ionizer 272 can be operated forapproximately 5 seconds to dissipate any static charges. Rail 116 isthen engaged to move apparatus 114 and the plate sheet 335 in thedirection of arrow 226, thereby moving the plate sheet 335 along the aircushion, and on to the input shelf 108 where the plate sheet 335 ispositioned and released for imaging.

FIG. 4, generally at 202, is a perspective view of an exemplaryembodiment of an interleaf sheet roller assembly. Rollers 402, 404 canbe provided with roller clutch bearings. The surface of rollers 402, 404is preferably made of a rubber or rubber-like material suitable forgripping interleaf sheets. Urethane or a urethane-like material can beused.

Axles, preferably made of metal (e.g., stainless steel), arerespectively received in holes 410, 412 of members 406, 408. The axlesare also similarly received in corresponding holes (not shown) ofmembers 414, 416. Members 406, 408 and 414, 416 rotate about hinge pin446. Members 406, 408 and 414, 416 are respectively arranged in ascissors-like configuration. A recess 442 can be provided on members406, 416 to limit the movement of members 408, 414 as the bottom portionof members 406, 408, 414, 416 move in the direction of arrows 448.Screws 434, 444 can be provided on members 406, 408, 414, 416 to holdthe axles in place so that they do not rotate relative to members 406,408, 414, 416. In this manner, roller clutch bearings (not shown) can beused to prevent rotation of rollers 402, 404 when rollers 402, 404 movetowards each other, in the direction of arrows 424.

Member 436 and hinge pin 446 form a single piece. Rod 418 is operablyconnected and/or in contact with a cutout surface 438 of member 436 andhinge pin 446 such that when rod 418 is pushed in the direction of arrow234, member 436 and hinge pin 446 can distribute the force to members406, 408, 414, 416, thereby causing members 406, 408, 414, 416 to movein the direction of arrows 448.

Members 406, 408 are respectively provided with holes 432, 450. Members414, 416 are provided with similar holes (not shown). Member 406 and itsrespective hole 432, and member 416 having a respective hole (notshown), receive link 430. Similarly, member 408 and its respective hole434, and member 414 having a respective hole (not shown) receive link428. One or more retaining rings 440 can be used to secure links 428,430 to respective members 408, 414 and 406, 416. Springs 420, 422 aresecured to links 428, 430 to provide a force in the direction of arrows424. The force increases as rollers 402, 404 move in the direction ofarrows 448. At equilibrium, springs 420, 422 can provide a force in thedirection of arrows 424 such that rollers 402, 404 contact each otherwith some amount of pinch force.

FIGS. 5A-5D show a sequence of positions of assembly 200 with respect tointerleaf sheet 502. FIG. 5A shows rollers 402, 404 contacting eachother with some amount of pinch force, and contacting interleaf sheet502. In FIG. 5B, a force is applied to rod 418 in the direction of arrow234, causing rollers 402, 404 to press outward in the direction ofarrows 448.

Rollers 402, 404 rotate freely with minimal bearing friction when movingin the direction of arrows 448. When moving in the direction of arrows448, rollers 402, 404 contact interleaf sheet 502, and can produce aconstant or variable contact force.

At a point where the outward spacing of the rollers is sufficient tograsp interleaf sheet 502 as shown in FIG. 5C at 508, the forces on therollers are changed such that rollers 402, 404 maintain a downward forceon interleaf sheet 502, while causing rollers 402, 404 to move towardeach other in the direction of arrows 424.

When rollers move in the direction of arrows 424, they are not free toroll on interleaf sheet 502. In an embodiment, standard clutch bearings(not shown) coupled to rollers 402, 404 in a conventional manner can beused to provide unidirectional rotation of the rollers 402, 404respectively in the direction of arrows 504, 506, and prevent rollers202, 204 from rotating when they move in the direction of arrows 424.Because rollers 402, 404 do not rotate when they move in the directionof arrows 424, interleaf sheet 502 “buckles up” into a small loop, asshown at 508 in FIG. 5C. The force of rollers 402, 404 against interleafsheet 502, together with the friction force created by the surface ofrollers 402, 404 with respect to interleaf sheet 502, overcome resistingforces between interleaf sheet 502 and the plate sheet below (notshown). Resisting forces may include, for example, the column strengthof interleaf sheet 502, static, suction, and/or frictional forcesbetween interleaf sheet 502 and the plate sheet below. As shown in FIG.5D, springs 420, 422 (spring 420 is not shown in Figure) pull rollers402, 404 in the direction of arrows 424 until the rollers 402, 404provide a pinch force that holds interleaf sheet 502 therebetween.

FIGS. 6A and 6B, generally at 600, respectively show a front view andperspective view of another embodiment of the invention. In particular,FIGS. 6A and 6B shows stationary foot (or thick block) 602, which can beused in lieu of roller 402 shown in FIG. 4. The positions of stationaryfoot 602 and roller 404 can also be switched. With the embodiment ofFIGS. 6A and 6B, curvilinear motion of rod 418 in the x-y plane replacesthe simple linear motion of rod 418 in the direction of arrows 234, 236in the embodiments of FIGS. 4 and 5A-5D.

FIGS. 7A and 7B, generally at 700, respectively show a front view andperspective view of another embodiment of the invention. In particular,FIGS. 7A and 7B shows stationary foot (or thin block) 702, which is usedin lieu of roller 402 shown in FIG. 4. The positions of stationary foot702 and roller 704 can also be switched. With the embodiment of FIGS. 7Aand 7B, curvilinear motion of rod 418 in the x-y plane replaces thesimple linear motion of rod 418 in the direction of arrows 234, 236 inthe embodiments of FIGS. 4 and 5A-5D.

FIGS. 8A-8D, generally at 800, shows another embodiment of theinvention, and a sequence of positions of assembly 800 with respect tointerleaf sheet 502. FIGS. 8A-8D show a substantially rigid Y-shapedlink 806, and non-circular rollers 802, 804 with one-way rollingrespectively in the direction of arrows 504, 506 when a force is appliedto rod 418 in the direction of arrow 234. The embodiment of FIG. 8 canbe used to create a cam-like pinch force with respect to interleaf sheet502. Rollers 802, 804 can be weighted and/or rolled about an axis offsetfrom the axis of the main curvature of the roller. Roller clutchbearings (not shown) can also optionally be used with rollers 802, 804to prevent rollers 802, 804 from respectively rotating in a directionopposite arrows 504, 506.

FIG. 9, generally at 900, is a perspective view of second embodiment ofan exemplary interleaf sheet removal apparatus. Pick up roller carriage901 can include axles 902 a, 902 b. Rollers 904 a, 904 b can beconfigured concentrically about axles 902 a, 902 b, and rotatetherewith. Rollers 904 a, 904 b can be positioned at or near the centerof plate sheets 335 and interleaf sheets, and contact each other tofacilitate removal of plate sheets 335 and interleaf sheets. One or moremotors (not shown) can be used to drive the axles 902 a, 902 brespectively in the direction of arrows 920, 922.

Transfer housing 906 a and 906 b can be connected to or integral withconnection housing 908. An optionally tapered opening 914 can beprovided at an end of transfer housing 906 a to receive interleaf sheetsfrom pick up roller carriage 901. One or more driven rollers 1 a-1 f canbe mounted to or integral with a first side of transfer housing 906 a,906 b. Rollers 1 a-1 f can be driven by a motor and belt (not shown).One or more blocks 924 can be connected to or integral with the firstside of transfer housing 906 a, 906 b, and rollers 1 a-1 f can beconnected to or integral with the respective blocks.

One or more non-driven rollers 2 a-2 f can be mounted to or integralwith a second side of transfer housing 906 a, 906 b. Rollers 1 a-1 f cancontact rollers 2 a-2 f so that rollers 2 a-2 f rotate with drivenrollers 1 a-1 f. A block 926 can be connected to or integral with thesecond side of transfer housing 906 a, 906 b, and rollers 2 a-2 f can beconnected to or integral with the respective blocks.

A suction cup apparatus, generally at 910, can optionally be providedand/or utilized in connection with interleaf sheet removal apparatus900. Suction cups 912 a, 912 b can be used to pick up plate sheets 335.Egress chute 918 can have a first end that receives interleaf sheetsfrom transfer housing 906 b, and a second end that allows the interleafsheets to exit.

FIG. 10, generally at 900, is a second perspective view of the secondembodiment of an interleaf sheet removal apparatus. Rail system 1006 canbe used to move pick up roller carriage 901 in the direction of arrows1002, 1004.

FIGS. 11A-11D is a sequence of operations showing how apparatus 900 canbe used to pick up an interleaf sheet. Pick up roller carriage 901 ispositioned near plate sheet and interleaf sheet stack 1102. Rollers 904a, 904 b, resting on an interleaf sheet, respectively rotate in thedirection of arrows 920, 922 to remove an interleaf sheet 1104 fromstack 1102. A disposal bin 1110 can be provided to receive interleafsheet 1104 as it exits egress chute 918.

As is shown in FIG. 11B, interleaf sheet 1104 is lifted off the platestack by rotating rollers 904 a, 904 b. Interleaf sheet 1104 can befolded, and pulled up between rollers 904 a, 904 b. Rollers 904 a, 904 bcan be stopped when a predetermined length of interleaf sheet 1104 hasbeen fed therethrough. A sensor (not shown) can be used to indicate thepredetermined length. For example, an optical sensor can be mountedabove rollers 904 a, 904 b such that when interleaf sheet 1104 is fedthrough rollers 904 a, 904 b, interleaf sheet 1104 will interrupt theoptical circuit, thereby indicating the predetermined length.

FIG. 11C shows that interleaf sheet 1104 is removed from stack 1102 asinterleaf sheet removal apparatus 900 traverses rails 1108 a, 1108 b inthe direction of arrow 1106. Rollers 904 a, 904 b feed the leading edgeof interleaf sheet 1104 to opening 914.

FIG. 11D shows interleaf sheet 1104 being driven by rollers 1 a-1 f, inconjunction with rollers 2 a-2 f to convey interleaf sheet 1104 throughtransfer housing 906 a, connection housing 908, and transfer housing 906b. Rollers 1 a-1 f and 2 a-2 f can continue to rotate until a trailingedge of interleaf sheet 1104 has cleared rollers 1 a, 2 a. A sensor,such as an optical sensor, positioned at or near rollers 1 a, 2 a, canbe used to indicate when the sheet has cleared. As the trailing edge ofinterleaf sheet 1104 exits rollers 1 a, 2 a, interleaf sheet 1104 can beplaced into disposal bin 1110. Interleaf sheet removal apparatus 900 canthen move in the direction of arrow 1112, to return to the positionshown in FIG. 11A, and receive another interleaf sheet 1104.

High Speed Dual Pick Up Arm Apparatus

In FIGS. 12 to 17, a high-speed dual pick up apparatus is described. Aperspective view of such apparatus 1500 is presented in FIG. 12.

The device depicted in FIGS. 12 to 17 preferably separates the interleafremoval mechanism from the plate pick up mechanism by utilizing twoseparate arm assemblies. The interleaf removal mechanism is on one armassembly, and the plate pick up mechanism is on another arm assembly.The arms function independently of each other, but they both travel onthe same rail system, thereby eliminating the cost of a second railassembly. The rail is extended to accommodate the additional arm.

Separating the functions onto two arm assemblies allows the machine toload plates much faster into the imager than prior art devices becausethe arm does not have to let one operation finish before it starts thenext. The arms work simultaneously to limit the waiting period betweenoperations. This greatly increases throughput of the machine. In oneembodiment, the CTP machine with the new dual pick up arm system canoutput 120 or more plates per hour compared to prior art machines, whichtypically output 60 plates per hour.

The operation of the new design is as follows: The plate pick up armpicks up a plate in the cassette using the vacuum cups and then bringsthe plate to the input shelf to be registered on the pins. As soon asthe plate is out of the cassette, the interleaf sheet removal arm movesto pick up the interleaf sheet in the cassette. While the pick up arm isregistering the plate against the pins, the interleaf sheet arm ispicking up the interleaf sheet and the moving it to the disposal rollersand the rollers dispose the sheet in a holding bin below. The pick uparm finishes registering the plate and then only has to pausemomentarily to allow the interleaf arm to finish disposing the interleafsheet. Then the pick up arm can pick up the next plate.

The following figures show many of the same elements that are describedin FIGS. 1-11, and like elements are described by like numerals. In theremainder of this specification, only those elements which are notpresent in the prior Figures are discussed.

FIG. 12 is a perspective view of a Computer-to-Plate (CTP) imagingsystem 1500 that is similar to the system 100 depicted in FIG. 1 butdiffers therefrom in that the interleaf removal apparatus 2000 and theplate pick up apparatus 2001 are used in place of the interleaf sheetremoval and plate sheet transport apparatus.

FIG. 13 is a perspective view of one embodiment of a high-speed dualpick-up arm apparatus in a Computer-to-Plate (CTP) imaging system. Theinterleaf removal apparatus 2000 and the plate pick up apparatus 2001are used in place of the interleaf sheet removal and plate sheettransport apparatus 114.

FIG. 14 is a perspective view of one preferred embodiment of ahigh-speed dual pick-up arm apparatus. The rail apparatus 116 b issimilar to the rail apparatus 116 depicted in the prior Figures, exceptit is preferably longer to accommodate the two arm assemblies and hasadditional features to support the additional apparatus. Gearmotor 2002a moves the plate pick-up apparatus 2001 in the 226 and 228 direction.Gearmotor 2002 b moves the interleaf removal apparatus in the 226 and228 direction. Optical sensor 244 and flag 2248 (similar to element 248)are used to control the movement and position of the plate pick-upapparatus 2001. Optical sensor 2244 (similar to element 244) and flag2003 are used to control the movement and position of the interleafremoval apparatus 2000. Mounting plates 2222 a and 2222 b are similar tomounting plate 222.

FIG. 15 is a perspective view of the plate pick-up apparatus 2001. Theplate pick-up apparatus is similar to the plate pick up and interleafremoval apparatus 114 described in the prior Figures except it has nomeans to pick up an interleaf sheet. Motors 2210 a and 2208 and aresimilar to elements 210 and 208 described in the prior Figures exceptthe motors are optimized to be faster and to have increased life. Plateheight sensor member 2205 a and shaft 2264 a are similar to elements 205and 264 described in the prior Figures. In the embodiment depicted, athird vacuum cup 206 c is utilized to assist in registering the plate.Member 2202 a is similar to member 202 of the prior Figures except itonly has features for the vacuum cups.

FIG. 16 is a perspective view of the interleaf removal apparatus 2000.The interleaf removal apparatus uses the same scissor roller assemblies200 a and 200 b described in the prior Figures to pick up the interleafsheet as apparatus 114. Optical sensors 2006 are used to tell when thereis an interleaf sheet being held in the roller assembly 200 a and 200 b.Optical sensors 2206 are used to tell that the sheet beneath theinterleaf removal apparatus is indeed an interleaf sheet as opposed to aplate sheet or other unexpected sheet. The interleaf removal apparatus2000 has no vacuum cups to pick up plates and it does not need to movein the 230 and 232 directions depicted in the published patentapplication. Member 2202 b is similar to member 2202 a and 202. Motor2210 b is the same type motor as 2210 a and the method to raise andlower member 2202 b in directions 234 and 235 is similar to the methodto raise and lower members 2202 a and 202 on apparatus 2001 and 114.Spring plungers 1208 and 2005 assist in inserting interleaf sheetsbetween the disposal rollers 302 a and 302 b (see FIG. 17).

FIG. 17 is a side view of a portion of FIG. 13, showing interleaf sheet502 being released and disposed; this interleaf scissor mechanism issimilar to the mechanism shown in FIGS. 13-16 of published United Statespatent application 2006/0174790, that was based upon U.S. patentapplication Ser. No. 11/295,635, filed on Dec. 7, 2005. The entiredisclosure of such published patent application and of patentapplication Ser. No. 11/295,635 is hereby incorporated by reference intothis specification.

Referring again to FIG. 17, the device illustrated in such Figurediffers from the device depicted in FIGS. 13-16 of published patentapplication 2006/0174790 in that the method of opening the scissorsrollers to release the interleaf sheet differs. The scissors mechanism200 a is lowered in direction 234 by motor 2210 b (not shown) untilroller 204 a contacts the scissor release roller 2007 a. The scissormechanism is then lowered further in direction 234. Since roller 204 ais stopped by release roller 2007 a, the scissor mechanism 200 a pivotsand then opens and the interleaf sheet 502 is released. Roller 204 a hasa clutch which rotates freely in direction 506 and the release roller2007 a is a free spinning roller so there is no resistance pulling theinterleaf sheet 502 out of roller 204 a and 2007 a in direction 224.Another advantage of the free spinning release rollers is that there isvery little wear of the urethane roller 204 a. Scissor roller assembly200 b and release roller assembly 2007 b operate in the same way as 200a and 2007 a. Spring plungers 1208 and 2004 (not shown) push on theinterleaf sheet 502 so that the interleaf sheet positively contacts thedisposal rollers 302 a and 302 b. The disposal roller 302 a rotates indirection 304 a and disposal roller 302 b rotates in direction 304 b,thereby pulling the interleaf sheet.

The device depicted in FIGS. 12-17 provides many advantages. Separatingthe functions onto two arm assemblies allows the machine to load platesmuch faster into the imager than prior art devices because the arm doesnot have to let one operation finish before it starts the next. The armswork simultaneously to limit the waiting period between operations. Thisgreatly increases throughput of the machine. In one embodiment, theComputer to Plate machine with the new dual pick up arm system canoutput 120 or more plates per hour compared to prior art machines, whichtypically output 60 plates per hour.

FIGS. 12-17 also illustrate a new method for releasing the interleafsheets from the scissor mechanism. The interleaf removal arm moves theinterleaf sheet over the disposal rollers. The scissor mechanism islowered until the front roller of the scissor mechanism contacts arelease roller. Then the scissor mechanism is lowered further forcingthe scissors to open and release the interleaf sheet.

As will be apparent from such FIGS. 12-17, the device illustratedtherein operates as follows: The plate pick up arm picks up a plate inthe cassette using the vacuum cups and then brings the plate to theinput shelf to be registered on the pins. As soon as the plate is out ofthe cassette, the interleaf sheet removal arm moves to pick up theinterleaf sheet in the cassette. While the pick up arm is registeringthe plate against the pins, the interleaf sheet arm is picking up theinterleaf sheet and the moving it to the disposal rollers and therollers dispose the sheet in a holding bin below. The pick up armfinishes registering the plate and then only has to pause momentarily toallow the interleaf arm to finish disposing the interleaf sheet. Thenthe pick up arm can pick up the next plate.

1. A system for removing an interleaf sheet contacting a plate sheetused in an imaging system, comprising: (a) a substantially horizontalmember; (b) an assembly comprising at least two elements configured todirectly contact and pick up the interleaf sheet, a portion of saidassembly connected to said member; (c) a motor configured to move saidmember in a direction substantially perpendicular to a surface of theinterleaf sheet as positioned prior to contact; and (d) a first sensorsystem that generates a signal indicating when said member is a firstpredetermined distance from the interleaf sheet; (e) a second sensorsystem comprised of a second sensor that generates a signal indicatingthat the sheet beneath the second sensor is an interleaf sheet; saidmotor utilizing the first predetermined distance to move said member asecond predetermined distance from the interleaf sheet, the at least twoelements not contacting each other at the second predetermined distance,said motor moving said member in a direction toward the firstpredetermined distance to a position where at least a portion of theinterleaf sheet is interposed between the at least two elements.
 2. Thesystem as recited in claim 1, wherein said system further comprises athird sensor that generates a signal when said interleaf sheet isdisposed between said at least two elements.
 3. The system as recited inclaim 2, wherein said system is comprised of a first spring plunger. 4.The system as recited in claim 2, wherein said system is comprised of asecond spring plunger.
 5. The system as recited in claim 4, furthercomprising a disposal roller assembly that that receives said interleafsheet from said at least two elements.
 6. The system according to claim5, further comprising a rail assembly configured to move said at leasttwo elements to a position where said disposal roller assembly receivessaid interleaf sheet.
 7. The system according to claim 6, furthercomprising a member that is aligned beneath the each of said at leasttwo elements.
 8. The system according to claim 7, wherein the each ofsaid at least two members comprises a roller.
 9. The system according toclaim 7 wherein said horizontal member is lowered in a direction towardthe disposal roller assembly.
 10. A system according to claim 9, whereinas said horizontal member is lowered in the direction toward saiddisposal roller assembly, each of said at least two elements engages oneof said at least two members.
 11. The system according to claim 10,wherein as said horizontal member continues to move in the direction ofsaid disposal roller assembly, said at least one spring plunger directssaid interleaf sheet to said disposal roller assembly.
 12. The systemaccording to claim 11, wherein as said horizontal member continues tomove in the direction of said disposal roller assembly, each of said atleast two elements engaging said at least two members cause said atleast two elements to release said interleaf sheet to said disposalroller assembly.
 13. A method for removing an interleaf sheet contactinga plate sheet used in an imaging system, comprising: (a) providing asubstantially horizontal member; (b) providing an assembly comprising atleast two elements configured to directly contact and pick up theinterleaf sheet, a portion of the assembly connected to the member; (c)moving the member in a direction substantially perpendicular to asurface of the interleaf sheet as positioned prior to the at least twoelements contacting the interleaf sheet; (d) generating a first signalindicating the member is above an interleaf sheet (e) generating asecond signal indicating when the member is a predetermined distancefrom the interleaf sheet; (f) using the first predetermined distance tomove the member to a second predetermined distance from the interleafsheet, the at least two elements not contacting each other at the secondpredetermined distance; (g) moving the member in a direction toward thefirst predetermined distance to a position where at least a portion ofthe interleaf sheet is held between the at least two elements; and (h)generating a third signal indicating that the interleaf sheet is inplace between the at least two elements.